Scanning control system and method for magnetic resonance imaging system

ABSTRACT

An embodiment of the present invention provides a scanning control system for a magnetic resonance imaging system, comprising: a first 3D camera, configured to capture a three-dimensional image of a scan subject located on a scanning table of the magnetic resonance imaging system; a processing device, configured to identify body position information of the scan subject based on the three-dimensional image; and a control device, configured to set scanning parameters related to a body position based on the body position information.

TECHNICAL FIELD

Embodiments disclosed in the present invention relate to medical imagingtechnologies, and more specifically, to a scanning control system andmethod for a magnetic resonance imaging system.

BACKGROUND

Magnetic resonance imaging (MRI), as a medical imaging modality, canobtain three-dimensional images of the human body without using X-raysor other ionizing radiation. When a part of interest of a patient isimaged using a magnetic resonance imaging system, the part of interestof the patient needs to be scanned. Before a scanning task is performed,a pre-scanning task needs to be executed to make adequate preparationfor formal scanning. For example, it is needed to input patientinformation, help the patient with positioning, set scanning parameters,optimize the scanning parameters, and so on. For different purposes suchas improving image quality, simplifying the operation process, reducingoperation time, and increasing patient comfort, it is desired that amore precise and optimized control can be performed on the magneticresonance imaging system in each process of pre-scanning and scanning asfar as possible.

In the prior art, there is still room for optimization in both thepre-scanning process and the scanning process to meet increasingclinical diagnostic requirements. For example, before scanning, it isneeded to communicate with a patient many times or move the patient manytimes to position the patient onto a scanning table at a generallyappropriate position; since it is difficult to precisely align a part ofinterest of the patient with a scanning center, it takes a long time toadjust the position or the image quality is affected; due to impropersetting of scanning parameters or improper selection of a coil channel,the image quality is lowered or images cannot be used for lesion checkand thus additional scanning is needed.

SUMMARY

One embodiment of the present invention provides a scanning controlsystem for a magnetic resonance imaging system, comprising: a first 3Dcamera, configured to capture a three-dimensional image of a scansubject located on a scanning table of the magnetic resonance imagingsystem; a processing device, configured to identify body positioninformation of the scan subject based on the three-dimensional image;and a control device, configured to set scanning parameters related to abody position based on the body position information.

Optionally, the processing device is further configured to determine,based on the body position of the scan subject displayed in thethree-dimensional image, a slice position and angle for imagereconstruction, and send the determined slice position and angle to animage reconstruction unit of the magnetic resonance imaging system.

Another embodiment of the present invention further provides a scanningcontrol system for a magnetic resonance imaging system, comprising:

a 3D camera, configured to photograph a scanning table of the magneticresonance imaging system and a scan subject located on the scanningtable to obtain a three-dimensional image, wherein the scan subject iscoupled to an RF receive coil, and the RF receive coil comprises aplurality of coil units arranged in an array;

a processing device, configured to determine relative positioninformation of a part of interest of the scan subject and the RF receivecoil based on the three-dimensional image, and select a coil unitrequired to be turned on from the RF receive coil based on thedetermined relative position information; and

a control device, configured to turn on the selected coil unit.

Optionally, the RF receive coil comprises a first receive coil disposedin the scanning table and a second receive coil disposed on a bodysurface of the scan subject; the processing device is further configuredto identify, based on the three-dimensional image, a coupling manner inwhich the second receive coil is coupled to the scan subject, and selectall or one of the first receive coil and the second receive coil basedon the coupling manner in which the second receive coil is coupled tothe scan subject; the control device is configured to turn on the coilselected from the first receive coil and the second receive coil.

Optionally, when the first receive coil is selected, the processingdevice is configured to select a required coil unit from the firstreceive coil based on relative position information of the part ofinterest of the scan subject and the first receive coil; when the secondreceive coil is selected, the processing device is configured to selecta required coil unit from the second receive coil based on relativeposition information of the part of interest of the scan subject and thesecond receive coil.

Optionally, the first 3D camera is further configured to photograph afirst region to obtain a first environment image before a scanningprocess starts or after the scanning process ends, wherein the firstregion comprises a positioning region of the scanning table; theprocessing device is configured to compare the first environment imagewith a prestored first standard environment image; the control device isconfigured to indicate a maintenance state of the magnetic resonanceimaging system based on a comparison result of the first environmentimage and the first standard environment image.

Optionally, the system further comprises a second 3D camera configuredto photograph a third region to obtain the third environment imagebefore the scanning process starts or after the scanning process ends,wherein the first 3D camera and the second 3D camera are respectivelylocated on two sides of a magnet assembly of the magnetic resonanceimaging system, and the third region comprises a region located outsidea scanning chamber of the magnetic resonance imaging system and oppositeto a rear end of the scanning chamber; the processing device is furtherconfigured to compare the third environment image with a prestoredsecond standard environment image; the control device is furtherconfigured to indicate the maintenance state of the magnetic resonanceimaging system based on a comparison result of the third environmentimage and the second standard environment image.

One embodiment of the present invention provides a scanning controlmethod for a magnetic resonance imaging system, comprising:

obtaining a three-dimensional image, captured by a first 3D camera, of ascan subject located on a scanning table of the magnetic resonanceimaging system;

identifying body position information of the scan subject based on thethree-dimensional image; and

setting scanning parameters related to a body position based on the bodyposition information.

Optionally, the method further comprises: determining, based on the bodyposition of the scan subject displayed in the three-dimensional image, aslice position and angle for image reconstruction, and sending thedetermined slice position and angle to an image reconstruction unit ofthe magnetic resonance imaging system.

Another embodiment of the present invention provides a scanning controlmethod for a magnetic resonance imaging system, comprising:

obtaining a scanning table of the magnetic resonance imaging system anda scan subject located on the scanning table that are photographed by afirst 3D camera to obtain a three-dimensional image, wherein the scansubject is coupled to an RF receive coil, and the RF receive coilcomprises a plurality of coil units arranged in an array;

determining relative position information of a part of interest of thescan subject and the RF receive coil based on the three-dimensionalimage, and selecting a coil unit required to be turned on from the RFreceive coil based on the determined relative position information; and

turning on the selected coil unit.

Optionally, the RF receive coil comprises a first receive coil disposedin the scanning table and a second receive coil disposed on a bodysurface of the scan subject, the method further comprising:

identifying, based on the three-dimensional image, a coupling manner inwhich the second receive coil is coupled to the scan subject, andselecting all or one of the first receive coil and the second receivecoil based on the coupling manner in which the second receive coil iscoupled to the scan subject; and

turning on the coil selected from the first receive coil and the secondreceive coil.

Optionally, when the first receive coil is selected, a required coilunit is selected from the first receive coil based on relative positioninformation of the part of interest of the scan subject and the firstreceive coil; when the second receive coil is selected, a required coilunit is selected from the second receive coil based on relative positioninformation of the part of interest of the scan subject and the secondreceive coil.

Optionally, the method further comprises: obtaining, before a scanningprocess starts or after the scanning process ends, a first environmentimage of a first region that is photographed by the first 3D camera,wherein the first region comprises a positioning region of the scanningtable; comparing the first environment image with a prestored firststandard environment image; and indicating a maintenance state of themagnetic resonance imaging system based on a comparison result of thefirst environment image and the first standard environment image.

Optionally, the method further comprises: obtaining, before the scanningprocess starts or after the scanning process ends, a second environmentimage of a third region that is captured by a second 3D camera, whereinthe first 3D camera and the second 3D camera are respectively located ontwo sides of a magnet assembly of the magnetic resonance imaging system,and the third region comprises a region located outside a scanningchamber of the magnetic resonance imaging system and opposite to a rearend of the scanning chamber; comparing the third environment image witha prestored second standard environment image; and indicating themaintenance state of the magnetic resonance imaging system based on acomparison result of the third environment image and the second standardenvironment image.

It should be understood that the brief description above is provided tointroduce in simplified form some concepts that will be furtherdescribed in the Detailed Description of the Embodiments. The briefdescription above is not meant to identify key or essential features ofthe claimed subject matter. The protection scope is defined uniquely bythe claims that follow the detailed description. Furthermore, theclaimed subject matter is not limited to implementations that solve anydisadvantages noted above or in any section of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood by reading the followingdescription of non-limiting embodiments with reference to theaccompanying drawings, where

FIG. 1 shows a block diagram of one example of a magnetic resonanceimaging system.

FIG. 2 shows a schematic structural diagram of a pre-scanning controlsystem according to one embodiment of the present invention.

FIG. 3 shows a schematic structural diagram of a pre-scanning controlsystem according to another embodiment of the present invention.

FIG. 4 shows a schematic structural diagram of a pre-scanning controlsystem according to another embodiment of the present invention.

FIG. 5 is an exemplary diagram of a spatial field gradient that varieswith position in a moving direction of a movable table board.

FIG. 6 is an exemplary diagram of a moving speed of the movable tableboard that varies with the position in the moving direction thereof.

FIG. 7 shows a schematic structural diagram of a pre-scanning controlsystem according to another embodiment of the present invention.

FIG. 8 , FIG. 9 , FIG. 10 , and FIG. 12 respectively show flowcharts ofone embodiment of a pre-scanning control method.

FIG. 11 shows a flowchart of one embodiment of controlling movement of ascanning table in FIG. 10 .

FIG. 13 shows a schematic structural diagram of a scanning controlsystem according to one embodiment of the present invention.

FIG. 14 shows an exemplary diagram of a scan subject in a plurality ofbody positions.

FIG. 15 shows a schematic structural diagram of a scanning controlsystem according to another embodiment of the present invention.

FIG. 16 shows a schematic structural diagram of a scanning controlsystem according to another embodiment of the present invention.

FIG. 17 and FIG. 18 respectively show flowcharts of a scanning controlmethod for a magnetic resonance imaging system according to oneembodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Various embodiments described below include a pre-scanning controlsystem and method for a magnetic resonance imaging system. FIG. 1 showsa block diagram of one example of a magnetic resonance imaging system.

As shown in FIG. 1 , the magnetic resonance imaging (MRI) system 100includes a scanner 110, a table 120, a controller unit 130, a dataprocessing unit 140, an operating console 150, and a display unit 160.

In one example, the scanner 110 may include a main magnet assembly 111.The main magnet assembly 111 usually includes an annular superconductingmagnet defined in a housing, where the annular superconducting magnet ismounted in an annular vacuum container. The annular superconductingmagnet and the housing thereof define a cylindrical space, namely, ascanning chamber 116 shown in FIG. 1 , surrounding a scan subject 16.The scanning chamber 116 defines an imaging region of the magneticresonance imaging system or at least part of the imaging region.

The main magnet assembly 111 is disposed in a scanning room. A firstregion 101, a second region 102, and a third region 103 may be definedoutside the main magnet assembly 111, wherein the first region 101 islocated outside the scanning chamber 116. Specifically, the first region101 may be a region where any scan subject resides before beingpositioned to the table 120 in the scanning room. The second region 102may be a region defining the table 120. The third region 103 may be aregion located outside the scanning chamber and opposite to a rear endof the scanning chamber. The rear end of the scanning chamber indicatesan end opposite to a patient entrance of the scanning chamber. Forexample, the third region 103 may include a positioning region for arear axle of the main magnet assembly 111.

The table 120 is used for carrying the scan subject 16, for example, apatient. The table 120 may include a lifting platform (not shown in thefigure) and a movable table board disposed on the lifting platform. Thetable 120 is generally fixed at a front end of the main magnet assembly111. The movable table board is used for carrying the scan subject 16,and configured to be able to communicate with the patient entrance ofthe scanning chamber 116, and move along the Z direction to allow thescan subject 16 thereon to enter and exit the scanning chamber 116 ortravel in the scanning chamber along the Z direction. That is, themovable table board may move from outside of the imaging region to animaging position in the imaging region, wherein the imaging position mayvary with a part to be imaged. The movable table board may also movestep by step between a plurality of imaging positions in the imagingregion to perform imaging of a plurality of imaging parts, such as wholebody imaging.

The scanner 110 further includes an RF transmit coil 112, aradio-frequency generator 113, a gradient coil assembly 114, a gradientcoil driver 115, an RF receive coil 170, and a data acquisition unit117. When an imaging scanning process is performed on a part of interestof the scan subject 16, the scanner 110 is configured to obtain imagedata of the scan subject 16.

Specifically, the main magnet assembly 111 generates a constant magneticfield, for example, a static magnetic field B0, in a Z direction of thescanning chamber 116. The MRI system 100 uses the formed static magneticfield B0 to emit a magnetostatic pulse signal to the subject 16 placedin the scanning chamber 116, so that the precession of protons in thebody of the subject 16 is ordered to generate a longitudinalmagnetization vector.

The radio-frequency generator 113 is configured to generate aradio-frequency pulse, for example, a radio-frequency excitation pulse.The radio-frequency excitation pulse is amplified (by, for example, aradio-frequency power amplifier (not shown)) and then applied to the RFtransmit coil 112, so that the RF transmit coil 112 emits to the scansubject 16 an RF magnetic field B1 orthogonal to the static magneticfield B0 to excite nuclei in the body of the subject 16, and thelongitudinal magnetization vector is converted into a transversemagnetization vector.

In one embodiment, the RF transmit coil 112 may be a body coil that maybe connected to a transmit/receive (T/R) switch (not shown). Thetransmit/receive (T/R) switch is controlled so that the body coil can beswitched between a transmit mode and a receive mode. In the receivemode, the body coil may be used for receiving the magnetic resonancesignal from the subject 16. The RF transmit coil 112 may also be a localcoil specifically used for a body part of the patient, such as a headcoil.

After the end of the radio-frequency excitation pulse, a free inductiondecay signal, namely a magnetic resonance signal that can be acquired,is generated in the process that the transverse magnetization vector ofthe subject 16 is gradually restored to zero.

The gradient coil assembly 114 forms a gradient magnetic field in theimaging space so as to provide three-dimensional position informationfor the magnetic resonance signal described above. The magneticresonance signal may be received by the RF receive coil 170 or a bodycoil in the receive mode.

The gradient coil assembly 114 may include three gradient coils. Each ofthe three gradient coils generates a gradient magnetic field inclined toone of three spatial axes (for example, X-axis, Y-axis, and Z-axis)perpendicular to each other, and generates a gradient field according toimaging conditions in each of a slice selection direction, a phaseencoding direction, and a frequency encoding direction. Morespecifically, the gradient coil assembly 114 applies a gradient field inthe slice selection direction of the subject 16 so as to select a slice;and the RF transmit coil 112 emits the RF excitation pulse to the sliceselected by the scan subject 16 and excites the slice. The gradient coilassembly 114 also applies a gradient field in the phase encodingdirection of the scan subject 16 so as to perform phase encoding on amagnetic resonance signal of the excited slice. The gradient coilassembly 114 then applies a gradient field in the frequency encodingdirection of the subject 16 so as to perform frequency encoding on themagnetic resonance signal of the excited slice.

The gradient coil driver 115 is configured to respectively provide asuitable power signal for the aforementioned three gradient coils inresponse to a sequence control signal transmitted by the controller unit130.

The RF receive coil 170 is configured to receive the aforementionedmagnetic resonance signal with the three-dimensional positioninformation. Depending on the imaging part, the RF receive coil 170 mayinclude a surface coil array unit attached to the surface of the scansubject 16, and the RF receive coil 170 may further include a surfacecoil array unit disposed on a side of a table 120 back against the scansubject 16. The RF receive coil 170 should be positioned at a part ofinterest sufficiently close to the scan subject 16 so as to receive amagnetic resonance signal with high quality.

The data acquisition unit 117 is configured to acquire the magneticresonance signal received by the RF receive coil 170. The dataacquisition unit 117 may include, for example, a radio-frequencypreamplifier, a phase detector, and an analog/digital converter, wherethe radio-frequency preamplifier is configured to amplify the magneticresonance signal received by the RF receive coil 170 or the body coil,the phase detector is configured to perform phase detection on theamplified magnetic resonance signal, and the analog/digital converter isconfigured to convert the phase-detected magnetic resonance signal froman analog signal to a digital signal.

The data processing unit 140 may perform processing such as calculationand reconstruction on the digitized magnetic resonance signal so as toobtain a required image or image data. The data processing unit 140 mayinclude a computer and a storage medium. A program of predetermined dataprocessing to be executed by the computer is recorded on the storagemedium. The data processing unit 140 may be connected to the dataacquisition unit 117 to receive the magnetic resonance signal output bythe data acquisition unit 117 so as to perform the aforementionedprocessing such as calculation and reconstruction. In one embodiment,the data processing unit 140 may include an image reconstruction unit141 configured to reconstruct an image of an anatomical structure of thescan subject 16 based on the aforementioned image data.

The controller unit 130 is coupled to the scanner 110, the table 120,the data processing unit 140, and the operating console 150, so as tocontrol corresponding components to perform required operations in apre-scanning process or a scanning process for magnetic resonanceimaging. For example, the controller unit 130 is configured to receiveand process an operating signal input to the operating console 150, andcontrol the working state of the aforementioned components such as thescanner 110 and the table 120 based on the operating signal. Theoperating signal may include, for example, protocols and parameters ofscanning selected manually or automatically, the starting and stopping,lifting up and down, moving speed, and the like of the table 120, andcommunication information with the scan subject such as positioningguidance and warning. The controller unit 130 also controls the dataprocessing unit 140 based on the operating signal received from theoperating console 150 so as to obtain the desired image.

The controller unit 130 may include a computer and a storage medium,wherein the storage medium is configured to store a program executableby the computer, and when the computer executes the program, thecomponents such as the scanner 110, the table 120, and the display unit160 are enabled to perform corresponding operations in the pre-scanningprocess, the scanning process, or an apparatus maintenance process. Thedata processing unit 140 is also enabled to perform predetermined dataprocessing.

In this embodiment, the controller unit 130 may control the starting andstopping, moving speed, and the like of the movable table board based onan operation instruction of a user or some detection signals, such thata part of interest of the scan subject 16 is positioned to be alignedwith a scanning center of the magnetic resonance imaging system (forexample, a center of the main magnet assembly) to facilitate imagingscanning on the part of interest. The controller unit 130 may further beconfigured to control other components of the scanner 110, the dataprocessing unit 140, and the display unit 160.

Before the part of interest of the scan subject 16 is positioned, anauxiliary apparatus may be used to help rapidly position the scansubject at an appropriate part of the table 120, thereby avoidingexcessive position adjustment of the scan subject for positioning thepart of interest.

The auxiliary apparatus may be a positioning guidance device 180 coupledto the magnetic resonance imaging system, for example, a projectionapparatus or an infrared apparatus for projecting a positioning markonto the table 120, wherein the positioning mark is used for guiding thescan subject to be positioned relative to the table 120 in thepre-scanning process. The positioning guidance device 180 may be mountedon a housing of the main magnet assembly 111 or fixed above the table120 in other mounting manners.

The storage media of the controller unit 130 and the data processingunit 140 may include, for example, a ROM, a floppy disk, a hard disk, anoptical disk, a magneto-optical disk, a CD-ROM, or a non-volatile memorycard.

The operating console 150 may include a user input apparatus, such as akeyboard and a mouse. An operator may input an operating signal/controlsignal to the controller unit 130 through the user input apparatus.

The display unit 160 may be connected to the operating console 150 todisplay an operation interface, and may further be connected to the dataprocessing unit 140 to display reconstructed images or various imagescaptured by a camera that is coupled to the magnetic resonance imagingsystem.

The MRI system 100 is described only as one example. In otherembodiments, the MRI system 1 may have a plurality of transformations,as long as image data can be acquired from the imaging subject.

First Embodiment

FIG. 2 shows a schematic structural diagram of a pre-scanning controlsystem according to one embodiment of the present invention. Thepre-scanning control system is used in a magnetic resonance imagingsystem. For example, the pre-scanning control system may be coupled tothe magnetic resonance imaging system shown in FIG. 1 . The pre-scanningcontrol system may include a 3D camera 210, a processing device 220, anda control device 230.

The 3D camera is configured to obtain a three-dimensional image of thescan subject 16 located in the first region 101. As shown in FIG. 2 ,the 3D camera may be disposed at a higher position of the scanning room,for example, directly or obliquely above the table 120. The 3D cameramay be fixed by using a ceiling of the scanning room or an apparatus ata higher position of the magnetic resonance imaging system.

As one example, when the scan subject starts to enter the scanning room,the scan subject 16 may be guided to pass through the first region 101or stay briefly in the first region, so that the 3D camera canphotograph the scan subject 16.

In one example, the first region 101 is opposite to a patient entranceof the scanning chamber 116 with respect to the table 120. That is, thetable 120 is located between the first region 101 and the scanningchamber 116, and there is a space between the first region 101 and thetable 120 to avoid interference when the scan subject 16 isphotographed.

A captured first three-dimensional image at least includes a positioningpart 161 and a part 162 of interest of the scan subject 16. Thepositioning part 161 is a feature part of a human body for ease ofrecognition in the image, for example, the hip.

The processing device 220 is configured (programmed) to determine firstpositioning information of the scan subject 16 based on a positionalrelationship between the positioning part 161 and the part 162 ofinterest of the three-dimensional image. The first positioninginformation is positioning information of the scan subject relative tothe table 120 when the scan subject is subjected to an imaging scan. Forexample, the first positioning information may be used for indicatingthe position of the table 120 at which the positioning part 161 of thescan subject should be located, so that the part 162 of interest canexactly be opposite to a receive coil coupled within 120.

The part 162 of interest may be a part to be subjected to imagingdiagnosis. The processing device 220 may determine a part of interest tobe imaged according to a scanning protocol selected by a user throughthe operating console 150 and identify the part of interest in thethree-dimensional image.

In one embodiment, the processing device 220 is configured to calculatea distance D1 between the positioning part 161 and the part 162 ofinterest in the three-dimensional image, and calculate the firstpositioning information based on the distance D1 and second positioninginformation of the pre-identified part 162 of interest relative to thetable 120.

The second positioning information is predetermined based on a positionof the receive coil matching the part of interest relative to the table120. In one embodiment, the receive coil is disposed in the movabletable board of the table 120, and the second positioning information maybe position information of the receive coil coupled in the table 120relative to the table 120.

For example, assuming that the position where the receive coil coupledto the table 120 is denoted as I1, the position having a distance D1from the point I1 is a positioning point of the positioning part 161 ofthe scan subject on the table 120.

The control device 230 is configured to control the positioning guidancedevice 180 to send positioning guidance information based on theaforementioned first positioning information. As described above withreference to FIG. 1 , the positioning guidance device 180 may sendpositioning guidance information by projecting a guidance mark. Forexample, a guiding mark M1 is projected at the aforementionedpositioning point of the table 120 to indicate that the positioning part(for example, the hip) of the scan subject 16 is located at the guidingmark. In this way, the scan subject can first sit at the guiding markand then make the part of interest, such as the chest or another part,located exactly at an appropriate position (for example, at I1) whenlying down.

Optionally, the three-dimensional image captured by the 3D camera 210further includes at least two reference parts 163 and 164 of the scansubject 16. A height of lifting up and down of the table 120 may becontrolled based on information of the reference parts 163 and 164, sothat the scan subject 16 can more easily position the positioning part161 thereof at the aforementioned appropriate position of the table 120.Specifically, the processing device 220 is configured to determine theheight of the table 120 based on a positional relationship between thetwo reference parts 163 and 164 in the first three-dimensional image,and the control device 230 is configured to control 120 to be lifted upor down to the aforementioned height.

For example, the two reference parts 163 and 164 are respectively theknee part (for example, knee and knee pit) and foot (for example, sole,toes, and heel) of the scan subject, and the processing device 220determines the height of the table 120 based on a distance D2 betweenthe two reference parts 163 and 164. For example, the processing device220 calculates a height D2 that is suitable for the current subject 16to be scanned, while the current height of the table 120 is H1; then,the processing device 220 outputs H1-D2. When H1-D2 is greater than 0,the control device 230 controls the table 120 to be lifted down by H-D2;otherwise, the table 120 is controlled to be lifted up by D2-H.

The processing device 220 and the control device 40 may include acomputer and a storage medium, where the storage medium is configured tostore a program executable by the computer, and when the computerexecutes the program, the aforementioned positioning guidance of thescan subject can be implemented.

The processing device 220 and the control device 230 are preferablyintegrated with the computer and the storage medium of the magneticresonance imaging system, and may also be configured independently.

Second Embodiment

The above embodiment describes positioning of a part of interest of ascan subject to a position corresponding to a receive coil disposed inthe table 120. It should be understood that during magnetic resonanceimaging, a surface coil that can cover a human body may further be usedto receive magnetic resonance signals. It is usually desired that thesurface coil is placed to be close enough to the part of interest (forexample, the center of the part of interest opposite to the center ofthe surface coil), so that the received magnetic resonance signals havegood enough quality.

FIG. 3 shows a schematic structural diagram of a pre-scanning controlsystem according to another embodiment of the present invention. As oneexample, the pre-scanning control system may be used in the magneticresonance imaging system shown in FIG. 1 . The pre-scanning controlsystem provided in this embodiment can provideguidance/indication/warnings to a user so as to position the surfacecoil more rapidly. As shown in FIG. 3 , the pre-scanning control systemincludes a 3D camera 310, a processing device 320, and a control device330.

The 3D camera 310 may be the same apparatus as the 3D camera 210 or anapparatus mounted and disposed in a similar manner. The 3D camera 310 isconfigured to capture a three-dimensional image of a scan subject 16located in the second region 102 and a surface receive coil 171 coupledto the scan subject. For example, when the scan subject 16 lies down oris positioned on the table 120 in other postures advantageous toscanning, and when the surface receive coil 171 is in position (forexample, covers a part of interest of the human body), the 3D camera 310may be used to obtain a three-dimensional image of the scan subject 16and the surface receive coil 171 thereon.

The processing device 320 is configured (programmed) to determine, basedon a positional relationship between the surface receive coil 171 andthe scan subject 16 in the three-dimensional image, whether positions ofthe surface receive coil 171 and the part of interest of the scansubject match each other.

As one example, the processing device 320 may first respectivelyidentify the surface receive coil 171 and the scan subject 16 in thethree-dimensional image based on preset feature information of thesurface receive coil 171 and the scan subject 16, wherein the featureinformation may include one or more of information such as the size,profile, and depth. The processing device 320 may determine the positionof the part of interest in the identified scan subject based onpredetermined distribution information of human anatomical structures,or may estimate the position of the part of interest through, forexample, depth information, reflected in the three-dimensional image,wherein the position may be a range of position having a centerposition. The processing device 320 may further determine a centerposition of the identified surface receive coil, and determine whetherthe center position of the surface receive coil corresponds to thecenter position of the part of interest.

The control device 330 is configured (programmed) to control themagnetic resonance imaging system to issue a warning when positions ofthe surface receive coil 171 and the part of interest of the scansubject do not match. For example, the control device 330 may be coupledto the display unit 160 to control the display unit 160 to displaymismatch information, wherein the mismatch information may further showa relative positional relationship of two center positions, for example,an offset and an offset direction, so as to inform the user how toadjust relative positions of the surface receive coil and the part ofinterest of the scan subject 16. The control device 330 may further becoupled to a voice apparatus of the magnetic resonance imaging system toinform the user of the aforementioned mismatch information.

Certainly, in this manner, it may be further determined whether thepositions of the part of interest of the scan subject and the surfacereceive coil (for example, the surface receive coil 172 in FIG. 3 )disposed in the table 120 match each other. For example, the processingdevice 320 may first identify the table 120 and the scan subject 16 inthe image, and determine the position of the part of interest in theidentified scan subject. Since the position of the surface receive coil172 is fixed, that is, the surface receive coil has a predeterminedpositional relationship with respect to the table 120, therefore, theprocessing device 320 may further determine whether the position of thepart of interest matches the position of the surface receive coil, andif not, the processing device may also issue mismatch information forthe surface receive coil 172.

In one embodiment, when the same 3D camera is used to photograph thefirst region and the second region respectively, the control device 330is further configured to control a photographing angle of the 3D cameraso as to switch between a first photographing angle adapted to the firstregion 101 and a second photographing angle adapted to the second region102.

Third Embodiment

FIG. 4 is a schematic structural diagram of a pre-scanning controlsystem according to another embodiment of the present invention. As oneexample, the pre-scanning control system may be used in the magneticresonance imaging system shown in FIG. 1 . As shown in FIG. 4 , thepre-scanning control system includes a 3D camera 410, a processingdevice 420, a control device 430, and a storage device 440.

The storage device 440 is configured to store a standard human bodyimage, such as the image G1 (Golden Image) shown in FIG. 4 , wherein thestandard human body image shows a plurality of human anatomicalstructures, such as various organs and bones. A plurality of differentstandard human body images may be stored based on the age group, gender,or other classification standards, so as to invoke an image matching acurrent scan subject in a pre-scanning process.

The 3D camera 410 may be the same apparatus as the 3D camera 310 or anapparatus mounted and disposed in a similar manner. The 3D camera 410 isconfigured to photograph the scan subject 16 located on the table 120.For example, when the scan subject 16 lies down or is positioned on thetable 120 in other postures advantageous to scanning, the 3D camera 410may be used to obtain a three-dimensional image C1 (Camera Image) of thescan subject 16.

The processing device 420 is configured to identify a plurality offeature points 401 from the aforementioned three-dimensional image C1,and determine a matching image P1 (Patient Image) of the standard humanbody image based on distribution information of the identified featurepoints 401, wherein the feature points of the three-dimensional image C1can reflect body feature information of the scan subject 16, forexample, one or more of the body proportion, body profile, body height,and body thickness. For example, parts in the standard human body imageG1 (Golden Image) corresponding to the plurality of feature points maybe adjusted to a similar distribution by processing such as scaling,local scaling, and proportion adjustment, so that a plurality of humananatomical structures in the standard human body image G1 are adapted tobody features of the scan subject. In one example, the feature points401 may include a plurality of points of main joints of the human body.

The aforementioned matching image P1 may be presented to the userthrough the display unit 160 of the magnetic resonance imaging system. Aregion of interest may be determined based on an operation on thematching image P1. For example, an operator may select an anatomicalstructure of interest (hereinafter referred to as a matching anatomicalstructure) in the matching image through auxiliary tools such as points,lines, or boxes. For example, the operator may select a matchinganatomical structure 402 in the image P1 as a region of interest.

In other embodiments, the region of interest may be selected in othersmarter manners, for example, image recognition and machine learning.

The processing device 420 is further configured to identify the regionof interest selected from the matching image P1. The region of interestmay be mapped to a body part of the scan subject 16. Generally, before ascanning program is executed, the center of the region of interest ofthe scan subject 16 needs to be aligned with the scanning center, whichneeds to be implemented through movement of the table 120.

The control device 430 is coupled to the table 120 of the magneticresonance imaging system. Based on the region of interest identified bythe processing device 420, the control device 430 is configured tocontrol movement of the table 120, so as to position the body part ofthe scan subject 16 corresponding to the region of interest to a presetposition.

The aforementioned preset position may be an imaging position determinedin the imaging region, for example, a position in the scanning chamber116 opposite to the scanning center.

Fourth Embodiment

For example, in the magnetic resonance imaging system shown in FIG. 1 ,a main magnetic field provided by the main magnet assembly 111 is notuniform, and varies throughout the imaging region. The imaging regionmay be considered as having a spatial field gradient (for example,variation in field intensity in the Z direction), wherein the spatialfield gradient may be different in different ranges of position in theimaging region.

FIG. 5 is an exemplary diagram of a spatial field gradient that varieswith position in a moving direction (namely, the Z direction) of themovable table board. The horizontal axis in FIG. 5 represents a linearposition along the Z direction, and the vertical axis represents aspatial field gradient, wherein a positive displacement value and anegative displacement value with respect to a scanning center 550 areused to mark the linear position of the horizontal axis. In oneembodiment, the spatial field gradient is in units of Tesla/meter (T/m).According to FIG. 5 , the human body is subjected to a varying field atdifferent positions in the Z direction.

In addition, the amplitude of the spatial field gradient varies with thebody size of the patient. As an example, FIG. 5 shows three spatialfield gradient curves 510, 520, and 530 for patients with large, medium,and small size bodies respectively.

As shown in FIG. 5 , each of the curves 510, 520, and 530 has asubstantially similar shape. For example, at an entrance portion 501from −300 centimeters to −200 centimeters, the gradient is zero or nearzero. The entrance portion 501 corresponds to a range of position inwhich the brain of the human body is completely or almost completelyoutside a cavity 112 and a defined imaging region thereof.

Then, a first portion 502 of each gradient curve beginning at about −200centimeters corresponds to a portion in which the brain enters theimaging region and becomes close to the scanning center 550. At about−80 centimeters of the example shown, the gradient reaches a peak value503, and then the gradient decreases as the curve is closer to thescanning center 550.

A second portion 504 of each gradient curve is on the other side of thescanning center 550 and at a distance of about 20 centimeters from thescanning center 450, and corresponds to a position where the brain ofthe human body is at the scanning center 550 or near the scanning center550. For the second portion 504, the gradient is zero or relatively low.

If the brain of the human body further move forward and gradually awayfrom the scanning center 550, it would meet a third portion 505 of eachcurve. At about 80 centimeters of the example shown, the gradientreaches a peak value 506, and then the gradient decreases as the braingradually approaches a farther edge of the field in the imaging region.

It is generally believed that the brain of the human body is moreaffected by field variations than other parts of the human body.Moreover, the patient comfort is usually related to field variationswith time, rather than field variations with distance. As a result, thetraveling speed of the brain passing through different spatial gradientfields needs to be controlled to avoid discomfort or accidents.

Accordingly, FIG. 6 is an exemplary diagram of a moving speed of themovable table board that varies with the position in the movingdirection (Z direction) thereof. The horizontal axis in FIG. 6represents a linear position in the Z direction, which is specificallyrepresented by a positive displacement value and a negative displacementvalue with respect to the scanning center 550. The vertical axis in FIG.6 represents the maximum speed limit, namely, the safety speed, of themovable table board at the corresponding position. FIG. 6 shows threemoving speed curves 610, 620, and 630 for patients with large, medium,and small size bodies respectively. According to FIG. 6 , since thespatial field gradient is high for a patient with a large size, thespeed curve 610 includes speeds lower than other curves. Typically, eachcurve represents a low speed in the case of a high gradient and a highspeed in the case of a low gradient. Each of the curves 610, 620, and630 includes: a first position 602, corresponding to the first portion502 of the curve in FIG. 5 ; a second portion 604, corresponding to thesecond portion 504; and a third portion 605, corresponding to the thirdportion 505.

FIG. 7 shows a schematic structural diagram of a pre-scanning controlsystem according to another embodiment of the present invention. Thepre-scanning control system is used in a magnetic resonance imagingsystem. For example, the pre-scanning control system may be coupled tothe magnetic resonance imaging system shown in FIG. 1 . As shown in FIG.7 , the pre-scanning control system includes a 3D camera 710, aprocessing device 720, and a control device 730.

The 3D camera 710 may be the same apparatus as the 3D cameras 210, 310,410 or an apparatus mounted and disposed in a similar manner. The 3Dcamera 710 is configured to photograph the scan subject 16 on the table120. For example, when the scan subject 16 lies down or is positioned onthe table 120 in other postures advantageous to scanning, the 3D camera710 may be used to obtain a three-dimensional image of the scan subject16.

On one hand, the processing device 720 is configured (programmed) toobtain a curve of the moving speed of the table 120 varying with theposition in the Z direction, wherein the curve may be, for example, thecurve shown in FIG. 6 . The processing device 710 may, for example,obtain a spatial field gradient curve shown in FIG. 5 in advance, andthen obtain a speed curve of the table 120 shown in FIG. 6 based on thespatial field gradient curve. Speed curves corresponding to differentbody sizes may be prestored in the storage device coupled to theprocessing device 720, and the processing device 720 invokes acorresponding speed curve based on a body size of the scan subject thatis inputted in advance.

On the other hand, the processing device 720 is configured to identifythe head of the scan subject 16 in the three-dimensional image capturedby the aforementioned 3D camera, calculate a current position of thehead of the scan subject 16 based on an identification result, andpredict a moving speed of the scan subject 16 based on the currentposition of the head of the scan subject.

The control device 730 is configured to be coupled to a driver of thetable 120 and control the table 120 based on the predicted moving speedof the scan subject 16. For example, the scan subject may be moved morerapidly through portions (for example, the entrance portion 501 and thesecond portion 504) in which the spatial field gradient is relativelylow, and moved more slowly through portions (for example, the firstportion 502 and the third portion 505) in which the spatial fieldgradient is relatively high.

Upon completion of the scan, the moving speed of the table 120 can becontrolled in a similar manner according to the aforementioned spatialfield gradient, so as to move the scan subject 16 out of the scanningchamber.

Based on the above embodiment, the present invention may further providea pre-scanning control method for a magnetic resonance imaging system.FIG. 8 , FIG. 9 , FIG. 10 , and FIG. 12 respectively show flowcharts ofone embodiment of the pre-scanning control method. FIG. 11 shows aflowchart of one embodiment of controlling movement of a scanning tablein FIG. 10 .

As shown in FIG. 8 , in one embodiment, the pre-scanning control methodincludes steps S810 to S830.

In step S810, a first three-dimensional image, captured by a 3D camera,of a scan subject located in a first region outside a scanning chamberof the magnetic resonance imaging system is obtained, wherein the firstthree-dimensional image at least includes a positioning part (forexample, the hip) and a part of interest (for example, the chest) of thescan subject.

In step S820, when the scan subject is subjected to an imaging scan,first positioning information of the scan subject with respect to amagnetic resonance scanning table (for example, the table 120) isdetermined based on a positional relationship between the positioningpart and the part of interest of the first three-dimensional image.

In step S830, a positioning guidance device (for example, the device 180shown in FIG. 1 ) of the magnetic resonance imaging system is controlledto send positioning guidance information based on the first positioninginformation.

Step S820 may further include: calculating a distance between thepositioning part and the part of interest in the first three-dimensionalimage, and calculating the first positioning information based on thedistance between the positioning part and the part of interest andpredetermined second positioning information of the part of interestwith respect to the magnetic resonance scanning table.

Further, the second positioning information is determined based on aposition of a receive coil (for example, the receive coil 171) matchingthe part of interest with respect to the magnetic resonance scanningtable, and the receive coil is disposed on the magnetic resonancescanning table.

The aforementioned first three-dimensional image at least includes tworeference parts of the scan subject, for example, the knee and foot. Themethod shown in FIG. 9 includes steps S910 and S920.

In step S910, a height of the scanning table in the magnetic resonanceimaging system is determined based on a positional relationship betweentwo reference parts in the first three-dimensional image. In step S920,the scanning table is controlled to be lifted up or down to the height.

In step S910, the height of the scanning table may be determined basedon a distance between the two reference parts in the firstthree-dimensional image.

The scanning control method shown in FIG. 10 includes steps S1010 toS1050.

In step S1010, a second three-dimensional image, captured by a 3Dcamera, of a scan subject located on a scanning table (for example, thetable 120) of the magnetic resonance imaging system is obtained.

In step S1020, a plurality of feature points (for example, the featurepoints 401 in FIG. 4 ) is identified in the second three-dimensionalimage.

In step S1030, a prestored standard human body image (for example, theimage G1 in FIG. 4 ) is adjusted to a matching image (for example, theimage P1 in FIG. 4 ) adapted to body features of the scan subject basedon distribution information of the identified feature points.

In step S1040, a region of interest (for example, the region 402 in FIG.4 ) selected from the matching image is identified.

In step S1050, movement of the scanning table is controlled to positiona part of interest of the scan subject corresponding to the selectedregion of interest (for example, the chest of the patient correspondingto the region 402 of interest) to a preset position.

The controlling movement of the scanning table may further includecontrolling movement of the scanning table at a variable speed. FIG. 11shows a flowchart of one embodiment of controlling movement of ascanning table. As shown in FIG. 11 , the flow specifically includessteps S1110 to S1130.

In step S1110, position information of the head of the scan subject in amoving direction of the scanning table is calculated based on a secondthree-dimensional image. The position information of the head of thescan subject in the moving direction of the scanning table includes adistance between the head of the scan subject and a scanning center of amagnetic resonance imaging system.

In step S1120, moving speeds of the scanning table at differentpositions is estimated based on a predetermined curve of a moving speedof the scanning table varying with the position in the moving directionthereof.

In step S1130, movement of the scanning table at a variable speed iscontrolled based on the estimated moving speeds.

As shown in FIG. 12 , in one embodiment, the pre-scanning control methodincludes steps S1210 to S1220.

In step S1210, a third three-dimensional image captured by a 3D camera(for example, the 3D camera 310) is obtained, wherein the thirdthree-dimensional image includes a scan subject located on a scanningtable of the magnetic resonance imaging system and a surface receivecoil coupled to the scan subject.

In step S1220, the surface receive coil and a part of interest of thescan subject is identified in the third three-dimensional image, and itis determined by calculation whether the position of the surface receivecoil matches the position of the part of interest, wherein when theposition of the surface receive coil does not match the position of thepart of interest, the magnetic resonance imaging system is controlled toissue warning information.

Fifth Embodiment

FIG. 13 shows a schematic structural diagram of a scanning controlsystem according to an embodiment of the present invention. The scanningcontrol system is used in a magnetic resonance imaging system. Forexample, the scanning control system may be coupled to the magneticresonance imaging system shown in FIG. 1 . The scanning control systemmay include a 3D camera 1310, a processing device 1320, and a controldevice 1330.

The 3D camera 1310 may be the same apparatus as the 3D cameras 210, 310,410, 710 or an apparatus mounted and disposed in a similar manner. The3D camera 1310 may be configured to photograph the scan subject 16located on the table 120. For example, when the scan subject 16 liesdown or is positioned on the table 120 in other postures advantageous toscanning, the 3D camera 1310 may be used to obtain a three-dimensionalimage of the scan subject 16. In one embodiment, when the 3D camera 1310is the same apparatus as the 3D camera 210, the photographing angle ofthe camera may be switched based on identification of different stagesof magnetic resonance imaging. For example, when the current stage isidentified as patient positioning, the 3D camera may be focused on theaforementioned scan subject in the first region; when the current stageis identified as a scanning stage, the 3D camera 1310 may be focused onthe scan subject 16 on the table 120. The photographing angle of the 3Dcamera may be switched by, for example, the control device 1330.

The processing device 1320 is configured to identify body positioninformation of the scan subject 16 based on the three-dimensional imagecaptured by the 3D camera 1310, wherein the body position information isused for representing a positioning direction and posture of the scansubject 16 on the table 120. FIG. 14 exemplarily shows a plurality ofbody positions of the scan subject.

The positioning direction may usually include, for example, head firstor feet first, namely, the head enters the scanning chamber first or thefeet enter the scanning chamber first when the table 120 is moved tomake the scan subject thereon enter the scanning chamber from theoutside. For example, the 4 body positions in the upper part of FIG. 14are head first, and the 4 body positions in the lower part are feetfirst. The positioning posture may include, for example, supineposition, left lateral decubitus position, right lateral decubitusposition, and prone position.

Typically, in a scanning stage of magnetic resonance imaging, a doctoror technician needs to input corresponding body position informationbased on a positioning direction and posture of a patient so as tosubsequently select an appropriate slice position for imagereconstruction. Sometimes, the body position information input by thedoctor or technician is inconsistent with the actual situation, so thatan image reconstructed by the magnetic resonance imaging system does notcorrespond to a lesion part of the patient. In this case, the patientoften needs to be re-scanned, causing waste of medical resources andemotional problems of the patient.

In this embodiment, the processing device 1320 may automaticallyidentify the aforementioned body position information of the scansubject 16 based on the three-dimensional image captured by the 3Dcamera 1310, so that the control device 1330 can set scanning parametersrelated to a body position based on the identified body positioninformation, wherein the scanning parameters may include body positioninformation, or may also include other parameters that change due to thechange in the body position. In this way, the aforementioned problemscaused by manual input of body position information are avoided, and thescanning setting time can be reduced. In one embodiment, the imagereconstruction unit 141 may determine a slice position and angle forimage reconstruction based on the set parameters related to the bodyposition, so as to obtain an image that facilitates disease diagnosis.

The body position information inputted in the conventional manner isusually general information. Taking lateral decubitus position forexample, a plurality of different postures of a patient may be included,and thus it is difficult for a slice position and angle selected in thesubsequent reconstruction process to more precisely correspond to alesion part.

Therefore, the processing device 1320 may further more preciselydetermine, based on the body position of the scan subject 16 displayedin the three-dimensional image, a slice position and angle for imagereconstruction, and send the determined slice position and angle to animage reconstruction unit (for example, the image reconstruction unit141 in FIG. 1 ) of the magnetic resonance imaging system. The sliceposition and angle are determined based on the real body position of thescan subject 16 displayed in the three-dimensional image. For example,the selected slice may not be limited to be in an X-Y plane, and mayfurther form an angle with the X-Y plane, so that an image reconstructedby the image reconstruction unit can more precisely correspond to alesion part or part of interest of the scan subject.

Sixth Embodiment

FIG. 15 shows a schematic structural diagram of a scanning controlsystem according to another embodiment of the present invention. Thescanning control system is used in a magnetic resonance imaging system.For example, the scanning control system may be coupled to the magneticresonance imaging system shown in FIG. 1 . The scanning control systemmay include a 3D camera 1510, a processing device 1520, and a controldevice 1530.

The 3D camera 1510 may be the same apparatus as the 3D cameras 210, 310,410, 710, 1310 or an apparatus mounted and disposed in a similar manner.

The 3D camera 1510 is configured to photograph the table 120 and thescan subject 16 located on the table 120 to obtain a three-dimensionalimage. The scan subject 16 is coupled to an RF receive coil, the RFreceive coil may include a first receive coil 171 disposed in the table120, and the first receive coil 171 includes a plurality of coil units1711 arranged in an array. Referring to FIG. 1 and FIG. 15 incombination, the first receive coil 171 may be disposed on a side of thetable 120 facing away the scan subject 16, a positional relationshipbetween the first receive coil and the table 120 is determined, and thepositional relationship may be represented by second relative positioninformation. Specifically, the second relative position information mayinclude a range of position or a central position of the coil unit 1711on the table 120.

When the first receive coil 171 is selected to be turned on, theprocessing device 1520 selects an appropriate coil unit 1711 in thefirst receive coil 171 to obtain image data of the scan subject. Forexample, the processing device 1520 may determine first relativeposition information of a part of interest of the scan subject 16 andthe table 120 based on the three-dimensional image captured by the 3Dcamera 1510, wherein the first relative position information mayspecifically represent a range of position or a central position of aregion 163 of interest of the scan subject 16 on the table 120. Theprocessing device 1520 may identify the table and the region 163 ofinterest of the scan subject in the three-dimensional image, andcalculate a positional relationship between the region 163 of interestand the table 120 that are identified as the first relative positioninformation.

The processing device 1520 further determines relative positioninformation of a part 162 of interest of the scan subject 16 and thefirst receive coil 171 based on the first relative position informationand the second relative position information, and determine a coil unit1711 required to be turned on in the first receive coil 171 based on therelative position information of the part 162 of interest of the scansubject 16 and the first receive coil 171. For example, the processingdevice 1520 determines a coil unit 1711 closer to the region 163 ofinterest of the scan subject 16.

The control device 1530 is configured to turn on the determined coilunit 1711. Specifically, the control device 1530 turns on the coil unit1711 by controlling a switch of the coil unit 1711.

An example of automatically selecting a coil unit when the first receivecoil 171 (namely, a receive coil coupled to the table 120 and determinedrelative to a position of the table 120) is used is described above. Anexample of automatically selecting a coil and a coil unit when a secondreceive coil 172 is used will be further described in the followingexample. The second receive coil 172 may be a receive coil disposed onthe body of the scan subject 16, and also includes a plurality of coilunits 1721 arranged in a matrix. According to different imagingrequirements, the second receive coil may be attached to one side of thebody of the scan subject 16 in a tiling/covering manner, or maysurround/wrap a part of the body of the scan subject 16. In the formermanner, the second receive coil generally covers an upper side (a sideaway from the table 120) of the scan subject, and the second receivecoil is used in combination with the first receive coil to obtainimaging data of the scan subject during scanning. In the latter manner,only the second receive coil may be used to obtain imaging data, and thefirst receive coil does not need to be used, but a doctor or atechnician sometimes inputs information inconsistent with the actualcoupling manner of coil during setting. For example, the second surfacecoil is tiled, and if the doctor or the technician sets as only usingthe second surface coil, obtained imaging data is incomplete, thequality of a reconstructed image is severely affected, and a scanningprocess usually needs to be performed again.

In the example of this embodiment, the processing device 1520 mayidentify, based on the three-dimensional image captured by the 3D camera1510, a coupling manner in which the second receive coil 172 is coupledto the scan subject 16, and select all or one of the first receive coil171 and the second receive coil 172 based on the coupling manner inwhich the second receive coil 172 is coupled to the scan subject 16. Thecontrol device 1530 is configured to turn on the coil selected from thefirst receive coil 171 and the second receive coil 172, which may bespecifically implemented by controlling switching of the first receivecoil and the second receive coil. For example, when the second receivecoil 172 is coupled to the scan subject in a tiling manner, the firstreceive coil and the second receive coil may be selected to be turnedon; and when the second receive coil 172 is coupled to the scan subjectin a surrounding manner, only the second receive coil may be selected tobe turned on.

In the example of this embodiment, when the second receive coil isselected, the processing device 1520 further determines relativeposition information of the part 162 of interest of the scan subject 16and the second receive coil 172 based on the three-dimensional imagecaptured by the 3D camera 1510, and determine a coil unit 1721 requiredto be turned on in the second receive coil 172 based on the relativeposition information of the part 162 of interest of the scan subject 16and the second receive coil 172. Similarly, a coil unit 1721 closer tothe region 163 of interest of the scan subject 16 can be determined.

Seventh Embodiment

FIG. 16 shows a schematic structural diagram of a scanning controlsystem according to another embodiment of the present invention. Thescanning control system may be coupled to the magnetic resonance imagingsystem shown in FIG. 1 . The scanning control system may include a 3Dcamera 1610, a processing device 1620, and a control device 1630.

The 3D camera 1610 may be the same apparatus as the 3D cameras 210, 310,410, 710, 1310, 1510 or an apparatus mounted and disposed in a similarmanner.

The 3D camera 1610 is configured to photograph the second region 102 toobtain a first environment image before a scanning process starts orafter the scanning process ends. As described above, the second region102 includes a positioning region of the table 120.

The processing device 1620 is configured to compare the firstenvironment image with a prestored standard environment image, andindicate a maintenance state based on a comparison result. Theaforementioned standard environment image displays an on-siteenvironment of the first region in a normal maintenance state, forexample, may include relative positions of various components, postures,and the like in the second region. If no scanning task is currentlyexecuted, on-site maintenance may be performed, and upon completion ofthe maintenance, a current image captured by the 3D camera 1610 may becompared with the standard environment image to determine whether themaintenance is improper. For example, when it is found that placement orposture errors exist in the current image, or redundant parts,components, or things exist as compared with the standard environmentimage, it indicates that the maintenance state is abnormal. At thistime, the control device 1630 may be used to control, for example, asound production apparatus, a display apparatus, or a light emittingapparatus, of the magnetic resonance imaging system to issue acorresponding warning. If the current image is consistent with thestandard environment image, it indicates that the maintenance state isnormal.

With reference to FIG. 1 and FIG. 16 in combination, similarly, the 3Dcamera 1640 may further be used to photograph the third region 103 toobtain a second environment image, and the second environment image iscompared with another prestored standard image, and a maintenance stateis indicated based on a comparison result.

FIG. 17 and FIG. 18 respectively show flowcharts of a scanning controlmethod for a magnetic resonance imaging system according to oneembodiment.

As shown in FIG. 17 , the method includes steps S1710 to 1730.

In step S1710, a three-dimensional image, captured by a first 3D camera,of a scan subject located on a scanning table (for example, the table120) of the magnetic resonance imaging system is obtained.

In step S1720, body position information of the scan subject isidentified based on the three-dimensional image.

In step S1730, scanning parameters related to a body position is setbased on the body position information.

Optionally, the method may further include: determining, based on thebody position of the scan subject displayed in the three-dimensionalimage, a slice position and angle for image reconstruction, and sendingthe determined slice position and angle to an image reconstruction unitof the magnetic resonance imaging system.

As shown in FIG. 18 , the method includes steps S1810 to S1830.

In step S1810, a scanning table of the magnetic resonance imaging systemand a scan subject located on the scanning table that are photographedby a first 3D camera is obtained to obtain a three-dimensional image,wherein the scan subject is coupled to an RF receive coil (for example,the first receive coil 171 and the second receive coil 172), and the RFreceive coil includes a plurality of coil units (for example, the coilunits 1711 and 1721) arranged in an array.

In step S1820, relative position information of a part of interest ofthe scan subject and the RF receive coil is determined based on thethree-dimensional image, and a coil unit required to be turned on isselected from the RF receive coil based on the determined relativeposition information.

In step S1830, the selected coil unit is turned on.

The method may further include: identifying, based on thethree-dimensional image, a coupling manner in which the second receivecoil is coupled to the scan subject, and selecting all or one of thefirst receive coil and the second receive coil based on the couplingmanner in which the second receive coil is coupled to the scan subject;and turning on the coil selected from the first receive coil and thesecond receive coil.

When the first receive coil is selected, a required coil unit isselected from the first receive coil based on relative positioninformation of the part of interest of the scan subject and the firstreceive coil. When the second receive coil is selected, a required coilunit is selected from the second receive coil based on relative positioninformation of the part of interest of the scan subject and the secondreceive coil.

The method may further include:

obtaining, before a scanning process starts or after the scanningprocess ends, a first environment image of a first region that isphotographed by the first 3D camera;

comparing the first environment image with a prestored first standardenvironment image; and

indicating a maintenance state of the magnetic resonance imaging systembased on a comparison result of the first environment image and thefirst standard environment image.

The method may further include:

obtaining, before the scanning process starts or after the scanningprocess ends, a second environment image of a third region (for example,third region 103) that is captured by a second 3D camera, wherein thefirst 3D camera and the second 3D camera are respectively located on twosides of a magnet assembly of the magnetic resonance imaging system, andthe third region comprises a region located outside a scanning chamberof the magnetic resonance imaging system and opposite to a rear end ofthe scanning chamber;

comparing the third environment image with a prestored second standardenvironment image; and

indicating the maintenance state of the magnetic resonance imagingsystem based on a comparison result of the third environment image andthe second standard environment image.

The above embodiments describe that a 3D camera is used to captureimages of different regions of a magnetic resonance scanning room,various analyses are performed on these images and a magnetic resonanceimaging system is automatically controlled based on analysis results, sothat pre-scanning and scanning processes of magnetic resonance imagingcan be performed more precisely and efficiently. For example, apositioning guidance mark is more precisely indicated to achieve preciseand rapid patient positioning; a positioning state of a receive coil isindicated to help an operator arrange a surface receive coil morerapidly and accurately; a matching state of the receive coil and a partof interest is indicated to avoid image quality problems caused byposition mismatch; the moving speed of a scanning table is estimated soas to ensure patient safety while rapidly moving the patient; a bodyposition is automatically detected to avoid resource waste and imagequality problems caused by errors in setting the body position, and moreprecise body position information enables reconstruction of imagesbetter reflecting patient lesions; a coupling manner in which a coil iscoupled to a subject is automatically detected to automatically select acoil, and a coil unit is automatically selected according to therelative position of the coil and the part of interest, so as to avoidresource waste and image quality problems caused by errors in selectingthe coil and the coil unit; an actual patient image and a standard humanbody structure image are used in combination to achieve rapid selectionof a region of interest.

The following embodiment will describe one example of implementingmagnetic resonance imaging using various embodiments of the presentinvention, wherein after a previous imaging process ends, a currentimaging process is started based on a user operation, and pre-scanningis performed:

a lens of a 3D camera is controlled to focus on a first region. The 3Dcamera may be controlled to photograph a patient in the first regionbased on a user operation, or the 3D camera may be used to monitorwhether there is a patient in position in the first region, and if yes,a first three-dimensional image is automatically obtained, and apositioning mark is projected on the table 120 based on an analysis ofthe first three-dimensional image, and the table 120 is adjusted to aheight adapted to the patient.

The lens of the 3D camera is focused on the region where the table 120is located automatically or based on the user operation.

The patient sits at the positioning mark and is then positioned on thetable 120 according to body position requirements.

The 3D camera is used to photograph the patient on the table 120 toobtain a second three-dimensional image, and the secondthree-dimensional image is used in combination with a prestored standardhuman body image to automatically determine and select a region ofinterest. This step may be performed in place of positioning scanning,or performed in combination with positioning scanning.

It is determined whether a part to be scanned (a part of interest) ofthe patient is positioned at an appropriate position based on ananalysis of the second three-dimensional image, and if not, the operatoror the patient is informed until the part of interest is positionedproperly.

After a surface coil is used to cover or surround a body part of thepatient, the 3D camera is controlled to capture a thirdthree-dimensional image based on an operation of the operator or anautomatic monitoring to result, wherein the third three-dimensionalimage includes the table, the patient, and the surface coil on the bodyof the patient. It is determined whether the surface coil is positionedopposite to the part of interest based on an analysis of the thirdthree-dimensional image, and if not, the operator is informed until thesurface coil is positioned properly.

A current relative position of the head of the patient is determinedbased on the second three-dimensional image, the third three-dimensionalimage, or another three-dimensional image obtained by photographing thepatient on the table 120 by the 3D camera, and moving speeds of thepatient at different travels in a traveling direction thereof (Zdirection) are estimated according to the relative position of the head.

Scanning is performed:

a body position of the patient is determined based on an analysis of thethird three-dimensional image and parameters related to the bodyposition are automatically set.

A coupling manner in which the surface coil is coupled to the patient isdetermined based on the analysis of the third three-dimensional image.For example, if in a covering manner, the surface coil and the receivecoil disposed in the table 120 are selected to be turned on; and if in asurrounding manner, only the surface coil is selected to be turned on.

A coil unit is further selected from the selected coil based on theanalysis of the third three-dimensional image.

The table 120 is controlled to move at the estimated speed, so as toposition the part of interest of the patient at a preset position, forexample, opposite to a scanning center.

Image data during scanning is obtained through the selected coil unit,and a reconstruction unit performs image reconstruction based on theimage data, wherein a slice angle and position are selected according tothe body position information.

The table 120 is controlled to move at the estimated speed, so as tomove the patient out of the scanning chamber 116.

The imaging process ends.

The order of describing the steps in the above example is not intendedto limit the actual order of execution, and there are a plurality ofvariable embodiments to complete the imaging process.

In various embodiments above, the processing unit and the control unitinclude a circuit that is configured to execute one or a plurality oftasks, functions or steps discussed herein. In various embodiments, theprocessing unit may be integrated with the data processing unit 120 ofthe magnetic resonance imaging system, and the control unit may beintegrated with the control unit 130 of the magnetic resonance imagingsystem. The “processing unit” and “control unit” used herein are notintended to necessarily be limited to a single processor or computer.For example, the processing unit and the control unit may include aplurality of processors, ASICs, FPGAs and/or computers, and theplurality of processors, ASICs, FPGAs and/or computers may be integratedin a common housing or unit, or may be distributed among various unitsor housings. The depicted processing unit and control unit include amemory. The memory 130 may include one or more computer-readable storagemedia. For example, the memory 130 may store information about systemcharacteristics (for example, information about spatial gradients),images (for example, standard human body images), algorithms orprocesses for performing any of the embodiments described above, and thelike. Further, the process flow and/or flowchart (or aspects thereof)discussed herein may represent one or more instruction sets stored inthe memory for guiding scanning control or pre-scanning control.

As used herein, an element or step described as singular and preceded bythe word “a” or “an” should be understood as not excluding such elementor step being plural, unless such exclusion is explicitly stated.Furthermore, references to “one embodiment” of the present invention arenot intended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features. Moreover, unlessexplicitly stated to the contrary, embodiments “comprising,”“including,” or “having” an element or a plurality of elements having aparticular property may include additional elements that do not havesuch property. The terms “including” and “in which” are used as theplain-language equivalents of the respective terms “comprising” and“wherein.” Furthermore, in the appended claims, the terms “first”,“second,” “third” and so on are used merely as labels, and are notintended to impose numerical requirements or a particular positionalorder on their objects.

This written description uses examples to disclose the presentinvention, including the best mode, and also to enable those of ordinaryskill in the relevant art to implement the present invention, includingmaking and using any devices or systems and performing any incorporatedmethods. The patentable scope of the present invention is defined by theclaims, and may include other examples that occur to those skilled inthe art. Such other examples are intended to be within the scope of theclaims if they have structural elements that do not differ from theliteral language of the claims, or if they include equivalent structuralelements without substantial differences from the literal language ofthe claims.

What is claimed is:
 1. A scanning control system for a magneticresonance imaging system, comprising: a first three-dimensional (3D)camera configured to photograph a scanning table of the magneticresonance imaging system and a scan subject located on the scanningtable to obtain a three-dimensional image, wherein the scan subject iscoupled to an RF receive coil, and the RF receive coil comprises aplurality of coil units arranged in an array; a second three-dimensional(3D) camera located on an opposite side of a magnet assembly of themagnetic resonance imaging system from the first 3D camera; processingcircuitry configured to determine relative position information betweena part of interest of the scan subject and the RF receive coil based onthe three-dimensional image, and select a coil unit from the pluralityof coil units required to be turned on from the RF receive coil based onthe determined relative position information, and wherein the processingcircuitry is configured to obtain, before a scanning process starts orafter the scanning process ends, both a first environment image of afirst region that is photographed by the first 3D camera and a secondenvironment image of a second region that is captured by the secondthree-dimensional (3D) camera, wherein the first region comprises apositioning region of the scanning table and the second region comprisesa region located outside a scanning chamber of the magnetic resonanceimaging system adjacent a rear end of the scanning chamber, and whereinthe processing circuitry is configured to compare the first environmentimage with a prestored first standard environment image and compare thesecond environment image with a prestored second standard environmentimage, and to indicate a maintenance state of the magnetic resonanceimaging system based both on a first comparison result of the firstenvironment image and the prestored first standard environment image anda second comparison result of the second environment image and thesecond standard environment image; and control circuitry configured toturn on the selected coil unit from the plurality of coil units.
 2. Thescanning control system of claim 1, wherein the RF receive coilcomprises a first receive coil disposed in the scanning table and asecond receive coil disposed on a body surface of the scan subject; theprocessing circuitry is further configured to identify, based on thethree-dimensional image, a coupling manner in which the second receivecoil is coupled to the scan subject, and select all or one of the firstreceive coil and the second receive coil based on the coupling manner inwhich the second receive coil is coupled to the scan subject; and thecontrol circuitry is configured to turn on the coil selected from thefirst receive coil and the second receive coil.
 3. The scanning controlsystem of claim 2, wherein the processing circuitry is configured toselect a required coil unit from the first receive coil based onrelative position information between the part of interest of the scansubject and the first receive coil upon selection of the first receivecoil, and wherein the processing circuitry is configured to select arequired coil unit from the second receive coil based on relativeposition information between the part of interest of the scan subjectand the second receive coil upon selection of the second receive coil.4. A scanning control method for a magnetic resonance imaging system,comprising: obtaining a three-dimensional image of a scanning table ofthe magnetic resonance imaging system and a scan subject located on thescanning table that are photographed by a first three-dimensional (3D)camera, wherein the scan subject is coupled to an RF receive coil, andthe RF receive coil comprises a plurality of coil units arranged in anarray; determining relative position information between a part ofinterest of the scan subject and the RF receive coil based on thethree-dimensional image, and selecting a coil unit from the plurality ofcoil units required to be turned on from the RF receive coil based onthe determined relative position information; turning on the selectedcoil unit from the plurality of coil units; and obtaining, before ascanning process starts or after the scanning process ends, both a firstenvironment image of a first region that is photographed by the first 3Dcamera and a second environment image of a second region that iscaptured by a second three-dimensional (3D) camera, wherein the first 3Dcamera and the second 3D camera are respectively located on oppositesides of a magnet assembly of the magnetic resonance imaging system,wherein the first region comprises a positioning region of the scanningtable and the second region comprises a region located outside ascanning chamber of the magnetic resonance imaging system adjacent arear end of the scanning chamber; comparing the first environment imagewith a prestored first standard environment image and comparing thesecond environment image with a prestored second standard environmentimage; and indicating a maintenance state of the magnetic resonanceimaging system based both on a first comparison result of the firstenvironment image and the prestored first standard environment image anda second comparison result of the second environment image and thesecond standard environment image.
 5. The method of claim 4, wherein theRF receive coil comprises a first receive coil disposed in the scanningtable and a second receive coil disposed on a body surface of the scansubject, and the method further comprises: identifying, based on thethree-dimensional image, a coupling manner in which the second receivecoil is coupled to the scan subject, and selecting all or one of thefirst receive coil and the second receive coil based on the couplingmanner in which the second receive coil is coupled to the scan subject;and turning on the coil selected from the first receive coil and thesecond receive coil.
 6. The method of claim 5, comprising selecting arequired coil unit from the first receive coil based on relativeposition information between the part of interest of the scan subjectand the first receive coil upon selection of the first receive coil; andselecting a required coil unit from the second receive coil based onrelative position information between the part of interest of the scansubject and the second receive coil upon selection of the second receivecoil.